1. Field of the Invention
The present invention generally relates to a heat engine converting thermal energy into kinetic energy, in particular, to a displacer type Stirling engine having double power output.
2. Description of Prior Art
Basically, Stirling engine is an external combustion engine with a reciprocating motion. A typical Stirling engine mainly includes two cylinders: one cylinder is heated by an externally heating source, while another cylinder is cooled by an externally cooling source. The two cylinders are communicated in a way, such that gas in the cylinders can be pushed to flow between two cylinders by means of a piston motion activated in the cylinders and then outputs external work through some mechanisms, such as connecting rod, crank, flywheel, etc, arranged between the two cylinders.
Besides the aforementioned “double cylinder” type, a “displacer” type is another kind of Stirling engine. The “displacer” type Stirling engine integrates the aforementioned two cylinders into one big cylinder, a bottom of which is designed as a heating position, and a top of which is designed as a cooling position. A displacer arranged in the big cylinder is not airtight and can be displaced upwardly and downwardly, making gas moved freely in the big cylinder. In addition, a smaller airtight piston (or so-called “power piston”) is arranged at a top of the big cylinder, when the displacer in the big cylinder is activated, because of an expansion and shrink of the gas in the big cylinder, the power piston can be displaced upwardly and downwardly to output work externally.
However, due to one big cylinder, conventional displacer type Stirling engine performs poorly as compared to the double cylinder type having double power output. Even having a double power output, the work made by the conventional double cylinder type Stirling engine is easily deteriorated because two powers respectively outputted from two cylinders that are not coaxial are unbalanced, and a runout phenomenon will occur.
Accordingly, aiming to solving the aforementioned shortcomings, after a substantially devoted study, in cooperation with the application of relatively academic principles, the inventor has at last proposed the present invention that is designed reasonably to possess the capability to improve the prior arts significantly.